Canadian Prime Minister Mark Carney told President Donald Trump Wednesday that his nation will retaliate against the United States with tariffs of its own if Trump presses forward with his promised levies – potentially escalating what is already developing into an ugly and damaging trade war.

The president has circled April 2 as the culmination of his "American first" economic policy, which has already shaken markets and started a trade war.

The new levies on cars and light trucks will take effect on April 3, the day after Trump plans to announce reciprocal tariffs aimed at the countries responsible for the bulk of the U.S. trade deficit.